Ethernet is based on packet switch technology, which involves communication of packets between various nodes (e.g., switches) of a network (e.g., a local area network (LAN)). The packets may be data packets or control packets, and different packets from a single endpoint may follow different paths in the network. It is possible to broadcast, on the underlying data-link layer in Ethernet networks, by addressing frames that are intended to reach every endpoint of a given LAN segment to a predefined media-access control (MAC) address (e.g., set to FF:FF:FF:FF:FF:FF) defined by the Internet Assigned Number Authority (IANA). The Ethernet broadcast nature may serve well in many applications where the topology changes are very dynamic such as core, enterprises, etc., but in some applications the change in topology may not be so dynamic, for example, mobile backhaul, or long distance transport between two continents, or a big fabric switch in a data center, where the path between many endpoints can be static.
Ethernet can have unicast and multicast addresses, where unicast MAC addresses are randomly distributed and are assigned to all ports of every device by the device manufacturer. The Ethernet multicast address is defined as any address with 40th bit set to 1. IANA has defined a reserved multicast MAC address as an address which is prefixed with 01-00-5E. With regard to multi-protocol labeled-switch transport profile (MPLS-TP) nodes, which may not be IP aware, IANA has recently defined a special Ethernet address: 01-00-5e-90-00-00.